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P0617: STARTER RELAY CIRCUIT HIGH Lexus SC II

Testing & Diagnostics 7 illustrations ~733 words

Note. For information on engine immobilizer system, see COMPUTERIZED ENGINE CONTROLS in THEORY & OPERATION article.

CAUTIONIf ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - LEXUS article.

Circuit Description

While engine is being cranked, battery positive voltage is applied to terminal STA of ECM. DTC will set if voltage is not present. (Scheme 164) Possible causes are

  1. Faulty starter relay.
  2. Faulty ignition switch.
  3. Faulty wire harness.
  4. Faulty ECM.

Scheme 164

Scheme 164
Scheme 164

Scheme 165

Scheme 165: Diagnosis & Repair (Using Hand-Held Tester)
Scheme 165: Diagnosis & Repair (Using Hand-Held Tester)

Scheme 166

Scheme 166
Scheme 166
  1. Read STA signal on the hand-held tester while the starter operates. With ignition switch on, STA signal should be off. With ignition switch in START position, STA signal should be on. If okay, problem is intermittent. If not okay, go to next step.
  2. Remove starter relay from the engine room No. 2 relay block. Check relay. See «STARTER RELAY CONTINUITY CHECK»(ref-151781-S03253347952003110700000) table. (Scheme 165) Replace relay as necessary. If relay is okay, go to next step. STARTER RELAY CONTINUITY CHECK Terminal No. Condition Specified Condition 1-2 Constant Continuity 3-5 Usually No Continuity 3-5 Apply Voltage Between Relay Terminals No. 1 & 2 Continuity
  3. Check ignition switch assembly. See IGNITION SWITCH in appropriate STEERING COLUMN SWITCHES article. Replace ignition or starter switch as necessary. If okay, go to next step.
  4. Check wire harness between the starter relay terminal No. 1 of relay block and ECM connector by inspecting STARTER fuse. Remove STARTER fuse from engine room No. 2 relay block. Check continuity of STARTER fuse. Remove STARTER relay from engine room No. 2 relay block. Check continuity between wire harness side connectors of ECM connector E6 terminal STA and starter relay terminal No. 1. (Scheme 166) If continuity is present, replace ECM. If continuity is not present, repair or replace harness and connector.

Note. Transmission range sensor is also referred to as park/neutral switch.

Park/neutral position switch detects shift lever position and sends signals to ECM. ECM receives signals (P, R, N, D, 4, 3, 2 and L) from the park/neutral position switch. When the shift lever is in the "4" position (with transmission control switch for "D" and "4" pressed), "4" in the shift position indicator light will come on, and when the shift lever is in the "D" position (with transmission control switch for "D" and "4" released), "D" in shift position indicator light will come on. When shift lever is in "L" position (with transmission control switch for "2" and "L" pressed), "L" in shift position indicator light will come on and when shift lever is in "2" position (with transmission control switch for "2" and "L" released), "2" in shift position indicator light will come on. (Scheme 167) Possible causes are

  1. Short in Park/Neutral Position (PNP) switch circuit.
  2. Faulty PNP switch.
  3. Faulty ECM.

Scheme 167

Scheme 167
Scheme 167

Diagnostic Aids

Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.

Scheme 168

Scheme 168: Diagnosis & Repair
Scheme 168: Diagnosis & Repair

Scheme 169

Scheme 169
Scheme 169

Scheme 170

Scheme 170
Scheme 170
  1. Disconnect park/neutral position switch 9-pin connector. (Scheme 168) Check continuity between each terminal when shift lever is moved to each position. See «PARK/NEUTRAL POSITION SWITCH CONTINUITY CHECK»(ref-151781-S33347621292003030500000) table. If continuity is to specification, go to next step. If continuity is not to specification, replace park/neutral position switch. PARK/NEUTRAL POSITION SWITCH CONTINUITY CHECK Shift Lever Position Continuity Between Terminals No. P 1-3, 6-9 R 2-3 N 3-5, 6-9 D, 4 3-7 3 3-4 2, L 3-8
  2. Reconnect park/neutral position switch connector. Disconnect shift lock control unit assembly 10-pin connector. (Scheme 169) Check continuity between each terminal when shift lever is moved to each position. See «SHIFT LOCK CONTROL ECU SUB-ASSEMBLY»(ref-151781-S36378040402003030500000) table. If continuity is present, go to next step. If continuity is not present, replace shift lock control ECU sub-assembly. SHIFT LOCK CONTROL ECU SUB-ASSEMBLY Shift Position Tester Connection Specified Value D 2-10 (AT4-NSSD) No Continuity 4 2-10 (AT4-NSSD) Continuity 2 3-6 (NSSL-ATL) No Continuity L 3-6 (NSSL-ATL) Continuity
  3. Reconnect shift lock control unit assembly connector. Disconnect ECM connectors. Turn ignition switch ON and measure voltage between terminals P, R, N, D, 4, 3, 2, and L of ECM and terminal E1 when shift lever is shifted to specified position. (Scheme 170) See «PARK/NEUTRAL POSITION SWITCH/ECM VOLTAGE CHECK»(ref-151781-S25920441042003030500000) table. Ensure battery voltage is present at each terminal. If voltage is to specification, replace ECM. If voltage is not to specification, repair or replace harness or connector. PARK/NEUTRAL POSITION SWITCH/ECM VOLTAGE CHECK Shift Lever Position ECM Terminal P P-E1 N N-E1 R R-E1 D, 4 D-E1 4 4-E1 3 3-E1 2, L 2-E1 L L-E1

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