#03-06-04-032: Check Engine Light On with No Driveability Concerns, DTC P0120, P0220, P1516, P1518 (Clear Code) - (Jun 16, 2003)
|Subject:||Check Engine Light On with No Drivability Concerns, DTC P0120, P0220, P1516, or P1518 Set (Clear Code)|
|Models:||2003 Cadillac Escalade, Escalade EXT, Escalade ESV|
|2003 Chevrolet Avalanche, Silverado, Suburban, Tahoe|
|2003 GMC Sierra, Yukon, Yukon XL|
|with 4.8L, 5.3L or 6.0L Engine (VINs V, P, T, Z, N, U - RPOs LR4, LM4, LM7, L59, LQ9, LQ4,)|
Some owners may comment that the Check Engine Light is illuminated and there is no driveability concern. Upon investigation, the technician may find codes P0120, P0220, P1516 or P1518. Also, technicians may note that low voltage codes P0562, P0563, P1637 or P1638 have been set.
The Tach module may set the code in error if it operates at a battery voltage of 4.5 to 5.0 volts.
If the vehicle has stored one of the low voltage codes, P0562, P0563, P1637 or P1638, follow the appropriate diagnostics for the low voltage code. In most cases, this will lead to correcting the concern without replacing any Electronic Throttle Control (ETC) components.
If codes P0120, P0220, P1516 or P1518 are present without any of the low voltage codes, the technician should observe the Engine RPM in the fault record.
| • ||If the Engine RPM in the fault record is zero and the customer indicates that the vehicles has experienced a low voltage condition, the code should be cleared and the low voltage should be diagnosed and corrected.|
| • ||If the Engine RPM is zero and the customer indicates that there have been no low voltage conditions, then the P1516 diagnostic aids for intermittent concerns should be used to diagnose and correct the vehicle|
| • ||If the Engine RPM is greater than zero, then check for an obvious loose ground at G103 located next to the right cylinder head just below the head and mounted into the block. Also, check G104 located behind the left cylinder head. Then verify all electrical connections at the TAC module.|
If the concern is still not resolved, contact Technical Assistance.
#PIP3087A: Crank, No Start, Stall, Hard Start, and No Cranking RPM - kw nostart nocrank 4.3 4.8 5.3 6.0 8.1 ignition information injector L18 L59 LM7 LQ4 LQ9 LR4 LU3 PCM L33 - (Oct 13, 2004)
|Subject:||Crank No Start, Stall, Hard Start, and No Cranking RPM.|
The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.
Crank no start, stalling, hard start, loss of cranking RPM, or loss of ignition 1 voltage. Depending on the model and the conditions present DTCS B3031, P0120, P0220, P0135, P0141, P0155, P0161, P1516, P1631, P2101 P2135, U1016 and U1064 may also be stored. It may also be noted that normal crank RPM registers momentarily as the key is released from the crank position.
If the "Engine Cranks but Does Not Run" SI diagnostics did not isolate a concern, the following information may help: Using the Tech 2, monitor the Ignition 1 voltage parameter when the customer concern is duplicated. With a fully charged battery, the Ignition 1 voltage parameter should not drop below 10 volts while cranking. If it does, measure the main voltage supply to the Underhood Bussed Electrical Center (UBEC) during the condition. If the UBEC voltage supply is above 10 volts but the Tech 2 Ignition 1 Voltage Parameter is below 10 volts, replace the Ignition 1 Relay.